/*
* Copyright (c) 2007, Nubo Technologies
* 
* All rights reserved.
* 
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
*
*    * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
*    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
*    * Neither the name of the Nubo Technologies nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

package com.nubotech.gwt.oss.client.s3;

import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.Response;
import com.google.gwt.xml.client.Document;
import com.google.gwt.xml.client.Element;
import com.google.gwt.xml.client.Node;
import com.google.gwt.xml.client.XMLParser;
import com.nubotech.gwt.oss.client.OnlineStorageServiceError;

/**
 *
 * @author jonnakkerud
 */
public abstract class AwsS3CallbackHandler implements RequestCallback {
        
    public Document getXml(Response response) {
        Document doc = null;        
        String xml = response.getText();
        if (xml != null && xml.length() > 0) {
            doc = XMLParser.parse(xml);
        }
        return doc;
    }
    
    protected String getElementTextValue(Element parent, String elementTag) {
        // If the xml is not coming from a known good source, this method would
        // have to include safety checks.
        return parent.getElementsByTagName(elementTag).item(0).getFirstChild().getNodeValue();
    }
    
    public boolean hasError(Response response) {
        boolean retval = false;
        if (response.getStatusCode() >= 300) {
            retval = true;
        }
        return retval;
    }
    
    protected OnlineStorageServiceError createError(Response response) {
        OnlineStorageServiceError error = null;
        if (response.getStatusCode() >= 400) {
            Document doc = getXml(response);
            if (doc != null) {
                Element rootElement = doc.getDocumentElement();
                XMLParser.removeWhitespace(rootElement);
                Node errorNode = rootElement.getElementsByTagName("Error").item(0);
                String message = getElementTextValue((Element) errorNode, "Message");
                String code = getElementTextValue((Element) errorNode, "Code");
                String resource = getElementTextValue((Element) errorNode, "Resource");
                error = new OnlineStorageServiceError(message, code, resource);
            }
        } else {
            error = new OnlineStorageServiceError(response.getStatusText(), String.valueOf(response.getStatusCode()), "");
        }
        return error;
    }
}
